Which of the following is a common indication of a pool leak?

A common indication of a pool leak is unexpectedly low water level. When a pool consistently loses water at an unusual rate, it often signals the presence of a leak. This decrease in water level may not necessarily correlate with evaporation, especially if it occurs rapidly or exceeds normal levels for evaporation in certain weather conditions.

In comparison, while sharp increases in chemical usage, frequent filter clogging, and regular algae blooms can suggest various issues within pool maintenance or minor inefficiencies, they do not specifically point to a leak. A rise in chemical usage could result from incorrect water balance or organic matter contributing to water quality issues. Filter clogging can occur due to debris or poor filtration systems rather than a leak. Lastly, algae blooms indicate poor sanitation or chemical imbalance, not necessarily a loss of water through leakage. Therefore, the most telling sign of a pool leak is the unexpected drop in the water level, as it directly suggests water is escaping the pool system.